Luminaires and components thereof

ABSTRACT

In one aspect, a lens comprises a light receiving side comprising grooves for receiving light emitting diodes, the grooves defined by refractive walls. The lens also comprises a light extraction side opposite the light receiving side, the light extraction side comprising refractive extraction surfaces diverging light from a central axis of the lens. In some embodiments, the refractive walls of the grooves work in conjunction with the refractive extraction surfaces to diverge light from the central axis of the lens. In some embodiments, luminaire comprises an array of light emitting diodes; and the lens positioned over the array of light emitting diodes.

RELATED APPLICATION DATA

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 16/786,619 filed Feb. 10, 2020.

FIELD

The present invention relates luminaires and optical components thereof.

BACKGROUND

Traditional high bay luminaires found in retail stores typically uselarge light source sizes, such as hundreds of mid-power light emittingdiodes (“LEDs”), in order to illuminate large areas of a retail floorspace. While LED arrays are very efficient, they often suffer frompixelation, where bright points of light from individual LEDs areobserved instead of a more comfortable uniform lighted surface typicallyassociated with incandescent or fluorescent lighting. Conventional highbay luminaires designs have struggled to produce pixelation-freeperformance while maintaining high efficacy and generating targetdistributions. Accordingly, improved luminaires and associated opticalcomponents, such as lenses are needed.

SUMMARY

In one aspect, optical components of luminaires are described herein. Insome embodiments, for example, a lens comprises a light receiving sidecomprising grooves for receiving light emitting diodes, the groovesdefined by a central refractive region and walls comprising totalinternal reflection faces. The lens also comprises a light extractionside opposite the light receiving side, wherein an axis bisecting thecentral refractive region forms an angle with a vertical axis of thelens ranging from greater than zero degrees to less than 90 degrees. Insome embodiments, the angle is from 5 to 60 degrees. The lightextraction side can comprise refractive extraction surfaces, totalinternal reflection extraction surfaces, or combinations thereof. Insome embodiments, the grooves are arranged in one or various linearformats.

In another aspect, a lens comprises a light receiving side comprisinggrooves for receiving light emitting diodes, the grooves defined byrefractive walls. The lens also comprises a light extraction sideopposite the light receiving side, the light extraction side comprisingrefractive extraction surfaces diverging light from a central axis ofthe lens. In some embodiments, the refractive walls of the grooves workin conjunction with the refractive extraction surfaces to diverge lightfrom the central axis of the lens.

In another aspect, luminaires are described herein. A luminairecomprises an array of light emitting diodes, and a lens positioned overthe array of light emitting diodes. The lens comprises a light receivingside comprising grooves for receiving the light emitting diodes, thegrooves defined by a central refractive region and walls comprisingtotal internal reflection faces. The lens also comprises a lightextraction side opposite the light receiving side, wherein an axisbisecting the central refractive region forms an angle with a verticalaxis of the luminaire ranging from greater than zero degrees to lessthan 90 degrees. In some embodiments, the angle is from 5 to 60 degrees.The light extraction side can comprise refractive extraction surfaces,total internal reflection extraction surfaces, or combinations thereof.In some embodiments, the central refractive region, TIR faces, and lightextraction surfaces of the lens work in conjunction to collimate ordirect light along the axis bisecting the central refractive region,thereby providing the desired lighting distribution of the luminaire.

In another aspect, the lens of the luminaire can comprise a lightreceiving side comprising grooves for receiving the light emittingdiodes, the grooves defined by refractive walls. The lens also comprisesa light extraction side, the light extraction side comprising refractiveextraction surfaces diverging light from a central axis of the lens.

In some embodiments, the luminaire further comprises a diffuserpositioned over the lens. The lighting distribution can in someinstances have a uniform luminance over the diffuser. The luminaire canfurther comprise a glare shield in some embodiments.

These and other embodiments are further described in the detaileddescription which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of a light receiving side of a lens havinggrooves arranged in a linear format.

FIG. 1B is a plan view of a light extraction side of the lens of FIG.1A.

FIG. 1C is a partial cross-sectional perspective view of the lens inFIG. 1A having an asymmetric light distribution pattern.

FIG. 1D is a cross-sectional perspective view of the lens in FIG. 1C.

FIG. 1E is a partial cross-sectional perspective view of the lens inFIG. 1A having a symmetric bi-directional light distribution pattern.

FIG. 1F is a cross-sectional perspective view of the lens in FIG. 1E.

FIG. 2A is a perspective view of an annular lens having a centralaperture.

FIG. 2B is a perspective view of a semicircular lens.

FIG. 2C is a perspective view of a helical and a tapered helical lens.

FIG. 2D is a graph of a linear lens having asymmetric and symmetriclight distribution patterns.

FIG. 3A is a plan view of a light receiving side of a lens havinggrooves arranged in a recti-linear format.

FIG. 3B is a cross-sectional perspective view of the lens in FIG. 3A.

FIG. 3C is a plan view of a light receiving side of a lens havinggrooves arranged in another recti-linear format.

FIG. 3D is a cross-sectional perspective view of the lens in FIG. 3C.

FIG. 4A is a cross-sectional perspective view of two individual lightelements of a lens.

FIG. 4B is a rayfan of the lens in FIG. 4A illustrating the centralrefractive region and TIR faces directing light received from an LEDlight source in a direction parallel to the central vertical axis of thelens.

FIG. 5A is a cross-sectional perspective view of two individual lightelements of a lens.

FIG. 5B is a rayfan of the lens in FIG. 5A illustrating the centralrefractive region and TIR faces directing light received from an LEDlight source in a direction parallel to the central vertical axis of thelens.

FIG. 6 is a cross-sectional perspective view light collimation by anindividual light element of a lens.

FIG. 7 is a schematic of an aisle luminaire employing a lens having anasymmetric light distribution described herein.

FIGS. 8A-8D each illustrate an asymmetric light distribution generatedby a lens in FIG. 1D.

FIGS. 9A-9D each illustrate a symmetric light distribution generated bya lens in FIG. 1F.

FIG. 10A is an exploded view of a luminaire described herein accordingto some embodiments.

FIG. 10B is an exploded view of a luminaire described herein accordingto some embodiments.

FIG. 11A is an exploded view of a luminaire described herein accordingto some embodiments.

FIG. 11B is an exploded view of a luminaire described herein accordingto some embodiments.

FIG. 12 is an exploded view of a luminaire, without a glare shield,according to some embodiments.

FIG. 13 is an exploded view of an exemplary luminaire having a lens witha central aperture and a sensor module.

FIG. 14 is an exploded view of an exemplary luminaire having a linearlens.

FIG. 15A is a plan view of a light receiving side of a lens according tosome embodiments.

FIG. 15B is a plan view of a light extraction side of a lens accordingto some embodiments.

FIG. 15C is a slanted cross-sectional view of a lens according to someembodiments.

FIG. 16A is a plan view of a light extraction side of a lens accordingto some embodiments.

FIG. 16B is a slanted cross-sectional view of the lens of FIG. 16A.

FIG. 17A is a plan view of a light extraction side of a lens accordingto some embodiments.

FIG. 17B is a slanted cross-sectional view of the lens of FIG. 17A.

FIG. 18 is a cross-sectional view of a section of a lens according tosome embodiments.

FIG. 19 is a rayfan diagram of a lens according to some embodiments.

FIG. 20 is a cross-sectional view of a lens illustrating edge facetsaccording to some embodiments.

FIG. 21 illustrates lighting distributions of luminaires employingvarious lens architectures according to some embodiments.

FIG. 22 illustrate lighting simulation results of the luminaires of FIG.21.

DETAILED DESCRIPTION

Embodiments described herein can be understood more readily by referenceto the following detailed description, examples, and figures. Elements,apparatus, and methods described herein, however, are not limited to thespecific embodiments presented in the detailed description, examples,and figures. It should be recognized that these embodiments are merelyillustrative of the principles of this disclosure. Numerousmodifications and adaptations will be readily apparent to those of skillin the art without departing from the spirit and scope of thisdisclosure.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of this disclosure. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present.Likewise, it will be understood that when an element such as a layer,region, or substrate is referred to as being “over” or extending “over”another element, it can be directly over or extend directly over theother element or intervening elements may also be present. In contrast,when an element is referred to as being “directly over” or extending“directly over” another element, there are no intervening elementspresent. It will also be understood that when an element is referred toas being “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Relative terms such as “top” or “bottom” or “below” or “above” or“upper” or “lower” or “horizontal” or “vertical” may be used herein todescribe a relationship of one element, layer, or region to anotherelement, layer, or region as illustrated in the Figures. It will beunderstood that these terms and those discussed above are intended toencompass different orientations of the device in addition to theorientation depicted in the Figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be further understood that the terms “comprises,” “comprising,”“having,” “includes,” and/or “including” when used herein specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

In addition, all ranges disclosed herein are to be understood toencompass any and all subranges subsumed therein. For example, a statedrange of “1.0 to 10.0” should be considered to include any and allsubranges beginning with a minimum value of 1.0 or more and ending witha maximum value of 10.0 or less, e.g., 1.0 to 5.3, or 4.7 to 10.0, or3.6 to 7.9.

All ranges disclosed herein are also to be considered to include the endpoints of the range, unless expressly stated otherwise. For example, arange of “between 5 and 10” or “from 5 to 10” or “5-10” should generallybe considered to include the end points 5 and 10.

The terms “lens” and “optic” are used interchangeably herein, and shouldbe understood as describing the same feature unless expressly statedotherwise.

I. Lenses

In one aspect, optical components of luminaires are described herein. Insome embodiments, for example, a lens comprises a light receiving sidecomprising grooves for receiving light emitting diodes, the groovesdefined by a central refractive region and walls comprising totalinternal reflection faces. The lens also comprises a light extractionside opposite the light receiving side, wherein an axis bisecting thecentral refractive region forms an angle with a vertical axis of thelens ranging from greater than zero degrees to less than 90 degrees. Thelight extraction side comprises refractive extraction surfaces, totalinternal reflection extraction surfaces, or combinations thereof.

The lens can be formed of any light transmissive material consistentwith the objectives of this disclosure. In some embodiments, the lens isformed of glass or radiation transmissive polymeric material. Suitableradiation transmissive polymeric materials include acrylics,polycarbonates, polystyrene, COPs (Cyclic Olefin Polymers), COCs (CyclicOlefin Copolymers), nylons, silicones and the like.

Turning now to specific features, the lens comprises a light receivingside and an opposite light extraction side. FIG. 1A illustrates a lightreceiving side 10 of lens 1 according to an embodiment, while FIG. 1Billustrates the light extraction side 20 of lens 1. Similarly, FIG. 1Cprovides a perspective cross-sectional view of the lens 1 of FIGS. 1Aand 1B. The lens can have a continuous surface over the diameter of thelens, as shown in the disc-shaped lens 1 of FIGS. 1A-1D. However, thelens is not limited to the continuous surface embodiment shown in FIGS.1A and 1B. In some embodiments, lens 1 can have a central aperture, suchas central aperture 24 shown in FIG. 2A. In other embodiments, lens 1can be semicircular in shape, as shown for example in FIG. 2B. Lens 1can also be formed in other shapes, such as a helical or tapered helicalshape of FIG. 2C. FIG. 2D illustrates various arrangements (asymmetricand symmetric bi-directional) of adjacent grooves 25 and associatedoptical surfaces.

The light receiving side comprises grooves for receiving light emittingdiodes (LEDs). The grooves can be arranged in any format notinconsistent with the objectives of this disclosure. The grooves canexhibit an isotropic or anisotropic arrangement over the light receivingside of the lens. For example, the grooves can be arranged in a linearformat, such as illustrated in FIGS. 1A-1C and 1E, where the grooves 11are arranged linearly in only one direction, along with extractionfacets in parallel.

In some cases, the grooves are arranged in a recti-linear format. FIGS.3A, 3B and 3C, 3D show a light receiving side 10 of lens 1 havinggrooves 11 arranged in different linear formats according to someembodiments. As illustrated in FIGS. 3A and 3C, radial sections of thelight receiving surface can exhibit differing linear arrangements of thegrooves. FIGS. 3B and 3D are cross-sectional perspective views of thelens in FIGS. 3A and 3C, respectively. The linearly arranged grooves canbe arranged in two axes with an angle between 0 and 90 degrees.

The number of, and dimensions of, grooves 11 can be selected accordingto various considerations including, but not limited to, size and/ornumber of the LEDs and the desired lighting distribution provided by thelens.

The grooves are defined by a central refractive region and wallscomprising total internal reflection (TIR) faces. The central refractiveregion can have any desired surface profile. In some embodiments, thecentral refractive region of the light receiving surface comprises aconvex surface, including spherical or aspherical convex surfaces. Thecentral refractive region can also exhibit other surface contours suchas combination of convex and concave surfaces, in some embodiments. Inaddition to the central refractive region, the grooves include wallscomprising TIR faces. In some embodiments, the TIR faces direct lightreceived by the lens to the light extraction side of the lens.

The light extraction side is opposite the light receiving side. Thelight extraction side comprises refractive extraction surfaces of anydesired contour not inconsistent with the technical objectives describedherein. In some embodiments, for example, the light extraction sidecomprises a convex surface in the central refractive region. The convexsurface of the light extraction side may have the same or a differentradius of curvature relative to the convex surface of the lightreceiving side. Alternatively, the light extraction side may be planaror concave in the central refractive region. Moreover, light extractionsurfaces receiving light from the TIR faces may be planar or curved, insome embodiments.

In some embodiments, the light extraction side can comprise the lightextraction facets, including the TIR facets. The facets can have anydesired geometry and/or dimensions. Facet geometry and/or dimensions,for example, can be selected according to the desired lightingdistribution from the lens, such as a narrow, wide, medium, orasymmetric lighting distribution. U.S. patent application Ser. No.16/558,964, filed Sep. 3, 2019, describes exemplary facet geometry,dimensions, and spatial arrangements and is incorporated in its entiretyherein.

As described herein, an axis bisecting the central refractive regionforms an angle with a vertical axis of the lens ranging from greaterthan zero degrees to less than 90 degrees. In some embodiments, thecentral refractive region, TIR faces, and light extraction faces of thelens work in conjunction to collimate or direct light along the axisbisecting the central refractive region. FIGS. 4A and 4B illustratecross-sections of a portion of a lens described herein, according tosome embodiments. In the embodiments of FIGS. 4A and 4B, the lenscomprises a light receiving side comprising grooves 11 for receivinglight emitting diodes 30, the grooves defined by a central refractiveregion 12 and walls comprising TIR surfaces 13. The light extractionside is opposite the light receiving side and comprises a convexextraction surface 23 in the central refractive region 12. The lightextraction side also comprises planar extraction surfaces 22 receivinglight from the TIR surfaces. An axis (A) bisecting the centralrefractive region 12 forms an angle (θ) with a vertical axis (B) of thelens. The angle (θ) is generally greater than zero degrees and less than90 degrees. In the embodiment of FIG. 4A, the bisecting axis (A) dividesthe central refractive region 12 into symmetric parts. It iscontemplated that in other embodiments, the bisecting axis (A) will passthrough the center of the central refractive region wherein suchsymmetry is not achieved. Symmetry or asymmetry between sections of thecentral refractive region on opposing sides of the axis (A) will bedependent upon the specific design of the central refractive region.

As illustrated in FIG. 4B, the central refraction region 12, TIRsurfaces 13 and extraction surfaces 22, 23 work in conjunction tocollimate or direct light from the LED 30 along the axis (A). Similarembodiments are also illustrated in FIGS. 5A, 5B and 6.

The lighting distribution of the lens, therefore, can be controlled oraltered according to the angle (θ). In some embodiments, each groove andassociated optical features have the same angle (θ). In otherembodiments, the angle (θ) can vary across the grooves of the lens.Angle (θ), in some embodiments, has a value selected from Table I.

TABLE I Values of angle (θ)  5-85 10-80 15-75 20-70 30-60 40-50

By adjusting the angle (θ), light distribution patterns can becontrolled and/or tailored. For example, when a lens according toembodiments described herein is used in an aisle light luminaire (suchas described in Section II), light from the luminaire can be customizedto illuminate shelving or racks on one or both sides of the aisle bysetting the appropriate angle of the grooves and associated opticalsurfaces. FIG. 7 illustrates an exemplary retail aisle having opposingshelving S that is illuminated with a luminaire having lens 1 with abi-direction light distribution pattern formed from lens according toembodiments herein, such as lens 1 having individual light elementsarranged as shown in FIGS. 1E and 1F or in the symmetric bi-directionalembodiment shown in FIG. 2D. The invention is not limited tobidirectional light distribution patterns, but can in other instanceshave a mono-directional (FIGS. 1B, 1C, and asymmetric I, II of 2D),tri-directional, tetra-directional, or any other number of directionallight distribution patterns. Additionally, the multi-directionaldistribution patterns can be symmetrically distributed or asymmetricallydistributed by variation in the number of individual light elementspositioned at the same angle θ. This level of control allows the lightdistribution to be tailored to selectively illuminate a desired targetarea, control beam spread, and/or control the intensity of the lightings(such as making one side brighter than the other in a bi-directionallight distribution pattern). In some cases, the light distributionpattern can be graduated and formed using the annular, semicircular, andhelical lens designs shown in FIGS. 2A-2C. Such graduated patterns can,for instance, be used to selectively illuminate curved racks andshelving, or in the case of the helical lens, provide architecturallighting with reduced glaring.

As previously discussed, the angle of light emitted from the lightextraction side 20 of lens can be controlled by angle θ. FIGS. 8A and 8Cshow simulated lighting distribution patterns from two differentluminaires employing a lens, where angle θ=20 degrees for each groove inthe lens 1. FIGS. 8B and 8D show simulated lighting distributionpatterns where angle θ=24 degrees for each individual groove in thelens.

In the embodiment shown in FIGS. 1E and 1F, the grooves of lens 1 aretilted in opposite directions to form a symmetrical bi-directionallighting pattern. FIGS. 9A and 9C show simulated lighting distributionpatterns from two different luminaires employing a lens describedherein, where θ=20 degrees and the grooves have a symmetricbidirectional orientation. Similarly, FIGS. 9B and 9D illustratesimulated lighting distribution patterns from two different luminairesemploying a lens described herein, where θ=24 degrees and the grooveshave a symmetric bidirectional orientation.

In another aspect, a lens comprises a light receiving side comprisinggrooves for receiving light emitting diodes, the grooves defined byrefractive walls. The lens also comprises a light extraction sideopposite the light receiving side, the light extraction side comprisingrefractive extraction surfaces diverging light from a central axis ofthe lens. In some embodiments, the refractive walls of the groove workin conjunction with the refractive extraction surfaces to diverge lightfrom the central axis of the lens.

Turning now to specific features, the lens comprises a light receivingside and an opposite light extraction side. FIG. 15A illustrates a lightreceiving side 10 of the lens 2, according to some embodiments, whileFIG. 15B illustrates the light extraction side 20 of the lens 2. Thelight receiving side 10 comprises grooves 22 for receiving lightemitting diodes. The grooves 22 can exhibit a periodic or aperiodicarrangement over the light receiving side 10 of the lens 2. In theembodiment of FIG. 15A, the grooves are arranged concentrically. FIG.15C provides a sectional view of the lens 2, further illustrating theconcentric arrangement of the grooves 22. However, the grooves may adoptany arrangement not inconsistent with the technical objectives describedherein. In some embodiments, the grooves are arranged in a linear formator a recti-linear format, such as that illustrated in FIGS. 16 and 17.

The grooves of the lens are defined by refractive walls. Refractivewalls defining the grooves can have any contour or profile consistentwith the technical objectives described herein. In some embodiments, forexample, the walls exhibit a smooth curved profile or contour that canbe approximated by one or more mathematical functions, such as quadraticfunctions. Alternatively, the walls can exhibit a stepped ordiscontinuous profile comprising linear and/or curvelinear sections. Insome embodiments, the refractive walls work in conjunction with thelight extraction side of the lens to diverge light from the central axisof the lens. FIG. 18 illustrates a cross-sectional view of a section ofa lens, according to some embodiments. In the embodiment of FIG. 18, thegrooves 30 are defined by refractive walls 31 having smooth contour andcurvature. The refractive walls 31 and refractive surfaces 35 candiverge light 33 received from the light emitting diode 32 from acentral axis (A) of the groove 30.

The light extraction side of the lens comprises refractive extractionsurfaces for diverging light from the central axis of the grooves. Therefractive extraction surfaces can have any contour or profileconsistent with diverging light from the central axis of the grooves. Insome embodiments, the refractive extraction surfaces can exhibit smoothcurved profiles, such as one or more convex surfaces. Alternatively, therefractive extraction surfaces can comprise one or more refractivefacets. In further embodiments, the refractive extraction surfaces cancomprise any combination of smooth surfaces and facets. In theembodiment illustrated in FIG. 18, the refractive extraction surfaces 35comprise intersecting convex surfaces. The refractive convex surfacesdiverge light 33 received from the light emitting diode 32 away from acentral axis (A) of the grooves. Moreover, the refractive walls 31defining the groove 30 also participate in diverging the light 33 awayfrom the central axis (A). FIG. 19 is a rayfan diagram illustratinglight paths through a lens having the architecture of FIG. 18. Asprovided in FIG. 19, light received from the light emitting diode isdiverged from the central axis of the groove by the refractive wallsdefining the groove in conjunction with the convex refractive extractionsurfaces. In some embodiments, the walls defining the groove and/or theextraction surfaces do not comprise any total internal reflection (TIR)surfaces.

In some embodiments, the lens spreads light received from the lightemitting diode in a manner that rays of the light do not overlap orinterfere with one another. As illustrated in the rayfan of FIG. 19, forexample, the individual rays are refracted at increasingly wider anglesas the convex surfaces extend from the central axis of the groove.Diverging light from the central axis of the groove permits light mixingbetween light emitting diodes of adjacent and/or concentric grooves.This light mixing can increase uniformity and reduce pixilation. Thismixing can also enhance diffuser performance for decreasing/eliminatingpixilation and providing uniform lighting output.

In addition, the light rays at such wider angles can form the wide lightdistribution of the associated luminaire, which is desirable for adistribution with Spacing Criteria >1.9.

In some embodiments, the lens comprises one or more light extractionfacets at the perimeter or edge of the lens. The extraction facets canmitigate any hot spots or non-uniformities resulting from the widerefraction angles provided by the refractive extraction surfaces of thelens, in some embodiments. The facets can comprise a plurality of planaror curved surface portions extending along a plane or curverespectively, which intersects with a plane or curve of an adjacentplanar or curved surface portion. Some of the adjacent planes or curvesintersect with unequal slopes. The extraction facets can compriserefractive surfaces, TIR surfaces or any combination thereof. In someembodiments, extraction facets can have any desired cross-sectionalgeometry including triangular or trapezoidal. The extraction facets canextend along the entire perimeter of the lens or only a portion thereof.The extraction facets can have any desired arrangement. In someembodiments, for example, the facets are concentric with one another.

FIG. 20 illustrates a sectional view of a lens including refractivefacets along the lens perimeter. As provided in FIG. 20, the facets 41exhibit a concentric arrangement at the perimeter of the lens 40 andpartially replace refractive extractions surfaces associated with theoutermost groove 42. In this way, pixilation, hot spots and/or otherlighting non-uniformities at the perimeter of the lens and/or associateddiffuser or glare shield are mitigated or eliminated.

Lenses described herein can have high optical efficiency. In some cases,the optical efficiency of fixtures with lenses can have an opticalefficiency 80-85%, 85-90%, 90-95%, or greater than 95%.

II. Luminaires

In another aspect, luminaires are described herein comprising lensesdescribed in Section I above. The luminaires can deliver symmetrical orasymmetrical lighting distributions. Luminaires described herein are notlimited to specific design and/or lighting application, and can providelight distributions as high bay fixtures, low bay fixtures, or anyfixture not inconsistent with the objectives of this disclosure. In someembodiments, luminaires are mounted on the ceiling. Alternatively, insome instances, luminaires can be mounted on a floor for delivery oflight to wall, floor, and/or ceiling surfaces.

Luminaires described herein, can comprise an LED light source, and alens described in Section I positioned over the LED light source. Thelens can have any design, construction and/or properties described inSection I herein. The LED light source can comprise an array of LEDs.FIGS. 10A to 11B show exploded views of different variations ofluminaires. In the embodiment shown in FIGS. 10A-11B, luminaires 100-400comprises an LED array 30 light source and a disc-shaped lens (optic) 1positioned over an LED light source 30. These four exemplary luminaireshave different diffuser 40 and shroud 50 options: two diffuser shapeswith an assembled location, and two glare shields (long and shallow).Luminaire 500 shown in FIG. 12 has the same general design as luminaires100-400, but omits the use of shroud 50 and uses only diffuser 40.Similarly for the embodiment shown in FIG. 13, luminaire 700 comprisesan LED array 30 light source and optic 1 positioned over an LED lightsource 30, where optic 1 has central aperture 24. Optic 1 can have anyconstruction and/or properties described in Section I herein, such asthose described for lens 1. Luminaire 800 of FIG. 14 varies in designfrom those of luminaires 100-700 in that optic 1 has a linear shaperather than the disc-like shape, such as those shown in FIG. 2D.

The LED light source can be arranged in an array format, includingone-dimensional LED arrays or two-dimensional LED arrays. In someembodiments, the LED array has a recti-linear or a concentric format. Asdescribed further herein, LEDs proximate the PCB edge can be eliminated,in some embodiments, to reduce pixilation, glare and/or other lightingnon-uniformities. The LED light source 30 shown generally in FIGS.10A-14 comprises an arrayed format on PCB (Printed Circuit Board) and alight emitting surface 31 onto which a two-dimensional array of LEDs arepositioned. Generally, the LED light source 30 has a shape complementaryto the shape of the optic 1. In the examples shown in FIG. 10A-12, LEDlight source 30 has an annular shape corresponding to the annular shapeof optic 1. However, the shape of the light source 30 is not limited toannular shapes, but can also have other shapes, such as in theembodiment shown in FIG. 13, where LED light source 30 has a centralaperture 54, and in FIG. 14, where LED light source 30 has a linear(e.g. rectangular) shape.

In some embodiments, a plurality of LEDs in the LED light source 30 aredistributed in a plurality of concentric rings having a spatial positioncorresponding to concentric grooves 11 formed on optic 1, such that whenthe optic 1 is positioned over the LED array 30, each of the LEDs ispositioned in or proximate to the grooves 11. In instances where thegrooves 11 are in a linear pattern rather than a concentric pattern, theLED array 30 would have a corresponding linear pattern such that each ofthe LEDs would be positioned in or proximate to the grooves 11 when thelinearly patterned optic 1 is positioned over the LED array 30 (see FIG.2D).

As used herein, the term “LED” can comprise packaged LED chip(s) orunpackaged LED chip(s). LED array 30 can use LEDs of the same ordifferent types and/or configurations. The LEDs can comprise single ormultiple phosphor-converted white and/or color LEDs, and/or bare LEDchip(s) mounted separately or together on a single substrate or packagethat comprises, for example, at least one phosphor-coated LED chipeither alone or in combination with at least one-color LED chip, such asa green LED, a yellow LED, a red LED, and the like. The LED array cancomprise phosphor-converted white or color LED chips and/or bare LEDchips of the same or different colors mounted directly on a printedcircuit board (e.g., chip on board) and/or packaged phosphor-convertedwhite or color LEDs mounted on the printed circuit board, such as ametal core printed circuit board or FR4 board. In some embodiments, theLEDs can be mounted directly to the heatsink or another type of board orsubstrate. Depending on the embodiment, the luminaire can employ LEDarrangements or lighting arrangements using remote phosphor technologyas would be understood by one of ordinary skill in the art, and examplesof remote phosphor technology are described in U.S. Pat. No. 7,614,759,assigned to the assignee of the present invention and herebyincorporated by reference.

In cases where a soft white illumination with improved color renderingis to be produced, each LED array 30 can include one or more blueshifted yellow LEDs and one or more red or red/orange LEDs as describedin U.S. Pat. No. 7,213,940, assigned to the assignee of the presentinvention and hereby incorporated by reference. The LEDs can be disposedin different configurations and/or layouts as desired, for exampleutilizing single or multiple strings of LEDs where each string of LEDscomprise LED chips in series and/or parallel. Different colortemperatures and appearances could be produced using other LEDcombinations of single and/or multiple LED chips packaged into discretepackages and/or directly mounted to a printed circuit board as a chip-onboard arrangement. In one embodiment, the LED array 30 comprises anyLED, for example, an XP-Q LED incorporating TrueWhite® LED technology oras disclosed in U.S. Pat. No. 9,818,919, granted Nov. 14, 2017, entitled“LED Package with Multiple Element Light Source and Encapsulant HavingPlanar Surfaces” by Lowes et al., the disclosure of which is herebyincorporated by reference herein, as developed and manufactured by Cree,Inc., the assignee of the present application. If desirable, other LEDarrangements are possible. In some embodiments, a string, a group ofLEDs or individual LEDs can comprise different lighting characteristicsand by independently controlling a string, a group of LEDs or individualLEDs, characteristics of the overall light out output of the luminairecan be controlled.

As shown in the embodiments of FIGS. 10A-14, luminaires 100-700 canfurther comprise one or more of a diffuser 40, glare shield 50, a sensorassembly 60, an LED driver 70, a heatsink 80, and trim ring 90.Additionally, for the embodiment of FIG. 14, luminaire 800 can comprisea reflector 95, a housing 96, and/or one or more housing endcaps 97.

Diffuser 40 can be made of any suitable diffuser material with lightdiffusing properties. The diffuser can permit concealment of anypixilated light beams while maintaining the desired light distributions.The diffuser, for example, can be constructed one or more polymericmaterials including, but not limited to, polycarbonate or acrylics. Insome embodiments, the lighting distribution provided by the array ofLEDs in conjunction with the lens has uniform luminance over thediffuser. The diffuser typically has a relatively high lighttransmission with lower diffusing properties, so that light is uniformlyilluminated across the surface of the diffusor, but the light isgenerally not redirected. In some embodiments, the diffuser can have alight transmission of 80-85%, 85-90%, 90-92%.

When present, the diffuser is positioned over the lens/optic. Thediffuser can be positioned directly on and in contact with the lens, orproximate to the lens. Alternatively, the diffuser can be positionedover the lens and spaced a distance away from the lens. In someembodiments, for example, the diffuser is placed 30-100 mm from thelens. Distance of the diffuser from the lens can be selected accordingto several considerations including, but not limited, to the arrangementof LEDs and/or the lighting distribution provided by the lens to thediffuser.

The diffuser can have any thickness suitable for the LED array and lensemployed in the luminaire. In some embodiments, the diffuser comprisesone or more tapered surfaces. The diameter of the diffuser, for example,can taper along the vertical axis of the diffuser. In some embodiments,the diameter is greatest at the base of the diffuser. Alternatively, thediameter can be greatest along the top surface of the diffuser.

As described herein, the luminaire can further comprise a glare shield.Glare shield or shroud 50 can be a monolithic element or can be formedof two or more segments having the same or differing optical properties.The glare shield 50 can comprise a clear or diffuse material that can beformed of any desired material including clear or translucent polymericmaterials, such as acrylic or polycarbonate. Alternatively, glare shield50 can be opaque, being formed from a non-translucent material,including metal. The shape and size of the glare shield 50 can vary,depending upon the desired application.

In some cases, the diffuser generates uplighting, which is lightpropagative into the opposite space to the main lighting space. Theuplighting can be generated by the diffuser scattering a smallpercentage of the light outward into the glare shield. The glare shieldsubsequently scatters some of the light to provide the uplighting. Anydesired amount of uplighting can be provided by the diffusor inconjunction with the glare shield. In some embodiments, the sidewall(s)of the diffuser can be tapered to alter the amount of light directed tothe glare shield for uplighting. The geometry of the glare shield mayalso be tailored to increase or decrease the amount of uplighting.Notably, the interaction between diffusor and glare shield design can beindependent of any lens design described herein. In some cases, 5-20% or10-15% of the luminaire output (lumens) is classified as uplight.Additionally, luminaires comprising lenses and architecture describedherein can have a spacing criteria (SC) greater than 1.9 or ranging from2 to 2.5, in some embodiments.

Luminaires employing lens architectures described herein can provide avariety of lighting distributions. FIGS. 9A-9D provide lightingdistributions of luminaire employing a lens comprising grooves definedby a central refractive region and walls comprising total internalreflection faces, according to some embodiments. FIG. 21 illustrateslighting distributions of luminaires comprising a lens including groovesfor receiving light emitting diodes, the grooves defined by refractivewalls. The lens comprises a light extraction side comprising refractiveextraction surfaces diverging light from a central axis of the lens. Theluminaires further comprise a polycarbonate diffuser and a glare shield.As provided in FIG. 21, two of the lenses comprise end facets describedherein, and two lenses do not have the end facets. Additionally, theterminology “Skip LEDs” refers to elimination of LEDs at the perimeterof the PCB. The lighting distributions of FIG. 21 include 15 to 17percent up-lighting, in additional to the symmetric down lightingcomponent.

FIG. 22 illustrates lighting results, including uniform luminance on thediffuser, of the luminaire having the distributions provided in FIG. 21.As illustrated in FIG. 22, full LEDs without end facets on the opticresulted in pixilation at the perimeter of the diffuser and shroud. Endfacets and LED skipping can each individually mitigate the pixilation,with the combination of the two providing elimination of the pixilation.

In the embodiment shown in FIG. 13, a sensor assembly 60 can bepositioned in a central aperture 24 of optic 1 and/or central aperture54 of LED array 30. Additionally, as described in more detail below,sensor assembly 60 can be positioned in a receiving space of heatsink80. Placement in the central aperture 24,54 can enable the sensorassembly 60 to connect directly to driver assembly 60, which can also bepositioned in the central aperture 24,54. In other embodiments, thesensor assembly is separate from and not integral with the luminaire andcan include networking, wired and/or wireless coupling to the luminaire.Further, the sensor assembly 60 can be recessed in the central aperture24,54, precluding light from the LED array 30 from directly striking thesensor assembly 60. The sensor assembly 60 can have one or more sensorsand/or functionalities including, but not limited to, low level lightimaging and/or occupancy detection. In other embodiments, other sensorassemblies can be used.

The invention is not limited to the sensor assembly being positioned ina central aperture of the optic 1. In other embodiments, a sensorassembly can be positioned in the end or proximate to glare shield 50,depending on the desired application.

In some embodiments, the sensor assembly can incorporate an effectivemotion detection system based upon a visible light focal plane arraysuch as a color or monochrome CMOS camera, in conjunction with imaginglens and digital processing. Physically, such motion detection sensormay closely resemble a camera module from a smartphone. Appropriatesensors may include those made by the Aptina division of OnSemiconductor, by Ominivsion or others. Appropriate lens assemblies mayresult in a sensor module field of view from 70 degrees to 120 degrees.Relatively inexpensive camera modules with resolution as low as(640×480) or (1290×960) can deliver fundamental ground sampledresolution as small as 2 cm from a height of 20 feet, more thansufficient to detect major and minor motions of persons or smallindustrial vehicles such as forklifts.

For operation in zero light environments, the sensor assembly cancomprise supplemental illumination provided by optional features, suchas a low-power near IR LED illuminator or a low power mode of theluminaire itself where the luminaire remains on at 0.5% to 10.0% of fullpower.

In various embodiments described herein various smart technologies maybe incorporated in luminaires described herein, such as in sensorassembly, as described in the following applications “Solid StateLighting Switches and Fixtures Providing Selectively Linked Dimming andColor Control and Methods of Operating,” application Ser. No.13/295,609, filed Nov. 14, 2011, which is incorporated by referenceherein in its entirety; “Master/Slave Arrangement for Lighting FixtureModules,” application Ser. No. 13/782,096, filed Mar. 1, 2013, which isincorporated by reference herein in its entirety; “Lighting Fixture forAutomated Grouping,” application Ser. No. 13/782,022, filed Mar. 1,2013, which is incorporated by reference herein in its entirety;“Multi-Agent Intelligent Lighting System,” application Ser. No.13/782,040, filed Mar. 1, 2013, which is incorporated by referenceherein in its entirety; “Routing Table Improvements for WirelessLighting Networks,” application Ser. No. 13/782,053, filed Mar. 1, 2013,which is incorporated by reference herein in its entirety;“Commissioning Device for Multi-Node Sensor and Control Networks,””application Ser. No. 13/782,068, filed Mar. 1, 2013, which isincorporated by reference herein in its entirety; “Wireless NetworkInitialization for Lighting Systems,” application Ser. No. 13/782,078,filed Mar. 1, 2013, which is incorporated by reference herein in itsentirety; “Commissioning for a Lighting Network,” application Ser. No.13/782,131, filed Mar. 1, 2013, which is incorporated by referenceherein in its entirety; “Ambient Light Monitoring in a LightingFixture,” application Ser. No. 13/838,398, filed Mar. 15, 2013, which isincorporated by reference herein in its entirety; “System, Devices andMethods for Controlling One or More Lights,” application Ser. No.14/052,336, filed Oct. 10, 2013, which is incorporated by referenceherein in its entirety; and “Enhanced Network Lighting,” applicationSer. No. 61/932,058, filed Jan. 27, 2014, which is incorporated byreference herein in its entirety.

LED driver 70 can include power or driver circuitry having a buckregulator, a boost regulator, a buck-boost regulator, a fly-backconverter, a SEPIC power supply or the like and/or multiple stage powerconverter employing the like, and may comprise a driver circuit asdisclosed in U.S. Pat. No. 9,791,110, granted Oct. 17, 2017, entitled“High Efficiency Driver Circuit with Fast Response” by Hu et al. or U.S.Pat. No. 9,303,823, granted Apr. 5, 2016, entitled “SEPIC Driver Circuitwith Low Input Current Ripple” by Hu et al., the entirety of theseapplications being incorporated by reference herein. The circuit mayfurther be used with light control circuitry that controls colortemperature of any of the embodiments disclosed herein, such asdisclosed in U.S. patent application Ser. No. 14/292,286, filed May 30,2014, entitled “Lighting Fixture Providing Variable CCT” by Pope et al.,the entirety of this application being incorporated by reference herein.Additionally, any of the embodiments described herein can include drivercircuitry disclosed in U.S. Pat. No. 9,730,289, granted Aug. 8, 2017,entitled “Solid State Light Fixtures Having Ultra-Low DimmingCapabilities and Related Driver Circuits and Methods”, the entirety ofthis application being incorporated herein by reference.

In some embodiments, LED driver 70 can comprise a driver assemblydisclosed in U.S. Pat. No. 10,234,127, granted Mar. 19, 2019, entitled“LED Luminaire Having Enhanced Thermal Management” by Bendtsen et al.,the entirety of this application being incorporated by reference herein.

Additionally, LED driver 70 can include the smart lighting controltechnologies disclosed in U.S. Patent Application Ser. No. 62/292,528,entitled “Distributed Lighting Network”, assigned to the same assigneeas this application, the entirety of the application being incorporatedherein by reference.

Any of the embodiments disclosed herein may be used in a luminairehaving one or more communication components forming a part of the lightcontrol circuitry, such as an RF antenna that senses RF energy. Suchcommunication components can in some instances be included in the LEDdriver 70 or in a separate driver communicatively connected to LEDdriver 70. The communication components may be included, for example, toallow the luminaire to communicate with other luminaires and/or with anexternal wireless controller, such as disclosed in U.S. patentapplication Ser. No. 13/782,040, filed Mar. 1, 2013, entitled “LightingFixture for Distributed Control” or U.S. Provisional Application No.61/932,058, filed Jan. 27, 2014, entitled “Enhanced Network Lighting”both owned by the assignee of the present application and thedisclosures of which are incorporated by reference herein. Moregenerally, the control circuitry can include at least one of a networkcomponent, an RF component, a control component, and one or moresensors. A sensor, such as a knob-shaped sensor, may provide anindication of ambient lighting levels and/or occupancy within the roomor illuminated area. Other sensors are possible, and a sensor may beintegrated into the light control circuitry as described herein, such asthose described with reference to sensor assembly 60.

LED heatsink 80 can comprise any heatsink structure not inconsistentwith the objectives of this disclosure. A typical LED heatsink comprisesa base having a radially extending mounting body, a central apertureformed in the mounting body, and a housing positioned proximate to thecentral aperture, and being connected, coupled, or attached to themounting body. The housing can comprise a component receiving space intowhich LED driver 70, various sensor components, backup battery, and thelike can be positioned and housed. In some embodiments, the heatsinkhousing and LED driver 70 can be combined into one unit to form a driverassembly described in U.S. Pat. No. 10,234,127, granted Mar. 19, 2019,entitled “LED Luminaire Having Enhanced Thermal Management” by Bendtsenet al., which has already been incorporated by reference in its entiretyherein. In some embodiments, sensor assembly 60 can connect, attach, orbe coupled to the mounting body or housing of the heatsink.

Finned structures extend from heatsink 80. In some cases, the finnedstructures are positioned around a central aperture of heatsink 80. Insome embodiments, finned structures are positioned on an upward facingsurface of mounting body. Finned structures can have any desired designincluding single fins, branched fins, curved fins and combinationsthereof. The finned structures, housing, and mounting body of heatsink80 can be independently formed of any suitable thermally conductivematerial.

In some embodiments, the finned structures, housing, and mounting bodyare formed of a material having thermal conductivity of 3-300 W/m K. Insome embodiments, finned structures, housing, and/or mounting body arefabricated from aluminum, steel sheet metal or other metal/alloy. Forexample, the finned structures, housing, and/or mounting body can befabricated from aluminum or other metal by die-casting. In someembodiments, the finned structures are fabricated independent of themounting body and subsequently coupled to the mounting body by one ormore techniques including fasteners, soldering, or bonding by adhesive.Such embodiments provide significant design freedom regardingcomposition and density of the finned structures. Similarly, in someinstances, the mounting body and housing of heatsink 80 are fabricatedindependently from each other, and subsequently coupled or connected byone or more techniques including fasteners, soldering, or bonding byadhesive. In some embodiments, the finned structures, housing, andmounting body are formed of the same material. In other embodiments, thefinned structures, housing, and mounting body are formed of differingmaterials. For example, the finned structures can be an extrudedpolymeric material or aluminum alloy, the housing a stamped sheet metal,and the mounting body a cast metal. Design and structure of the LEDheatsink 80 can be governed by several considerations, including coolingrequirements for the LED array and cost factors.

Various embodiments of the invention have been described in fulfillmentof the various objectives of the invention. It should be recognized thatthese embodiments are merely illustrative of the principles of thepresent invention. Numerous modifications and adaptations thereof willbe readily apparent to those skilled in the art without departing fromthe spirit and scope of the invention.

The invention claimed is:
 1. A lens comprising: a light receiving sidecomprising grooves for receiving light emitting diodes, the groovesdefined by refractive walls; a light extraction side opposite the lightreceiving side, the light extraction side comprising refractiveextraction surfaces diverging light from a central axis of the grooves;and one or more refractive facets at a perimeter of the lens.
 2. Thelens of claim 1, wherein the grooves are arranged in a concentricformat.
 3. The lens of claim 1, wherein the grooves are arranged in alinear format.
 4. The lens of claim 1, wherein the grooves are arrangedin a recti-linear format.
 5. The lens of claim 1, wherein the refractivewalls diverge light from the central axis of the groove.
 6. The lens ofclaim 1, wherein the refractive walls work in conjunction with therefractive extraction surfaces to diverge light from the central axis ofthe groove.
 7. The lens of claim 1, wherein the grooves exhibit periodicspacing across the lens.
 8. The lens of claim 1, wherein the groovesexhibit aperiodic spacing across the lens.
 9. The lens of claim 1,wherein light rays from a single light emitting diode do not intersectafter passing through the light extraction side.
 10. The lens of claim1, wherein the refractive extraction surfaces comprise two or moreintersecting convex surfaces.
 11. The lens of claim 1, wherein therefractive facets are concentric with one another.
 12. The lens of claim1, wherein the facets comprise a triangular cross-section.
 13. The lensof claim 1, wherein the facets comprise a splined shape cross-section.14. The lens of claim 1, wherein the refractive facets are along theentire perimeter of the lens.
 15. A luminaire comprising: an array oflight emitting diodes; and a lens positioned over the array of lightemitting diodes, wherein the lens comprises a light receiving sidecomprising grooves for receiving light emitting diodes, the groovesdefined by refractive walls, and a light extraction side opposition thelight receiving side, the light extraction side comprising refractiveextraction surfaces diverging light from a central axis of the grooves,wherein the lens further comprises one or more refractive facets at aperimeter of the lens.
 16. The luminaire of claim 15, wherein thegrooves are arranged in a concentric format.
 17. The luminaire of claim15, wherein the grooves are arranged in a recti-linear format.
 18. Theluminaire of claim 15, wherein the refractive walls work in conjunctionwith the refraction extraction surfaces to diverge light from thecentral axis of the grooves.
 19. The luminaire of claim 15, wherein therefractive extraction surfaces comprise two or more intersecting convexsurfaces.
 20. The luminaire of claim 15 further comprising a diffuserpositioned over the lens.
 21. The luminaire of claim 20, wherein lightrays from light emitting diodes proximate to one another interact on thediffuser.
 22. The luminaire of claim 20, wherein the diffuser that ispixilation free.
 23. The luminaire of claim 20 having a down lightingdistribution and up-lighting distribution.
 24. The luminaire of claim 20having up-lighting of 9% to 17%.